package com.bootdo.system.util;

import java.text.DecimalFormat;

public class LocationUtil {
private static double EARTH_RADIUS = 6378.137;    
    
    private static double rad(double d) {    
        return d * Math.PI / 180.0;    
    }    
    
    /**   
     * 通过经纬度获取距离(单位：米)   
     * @param lat1   
     * @param lng1   
     * @param lat2   
     * @param lng2   
     * @return   
     */    
    public static String getDistance(double lat1, double lng1, double lat2,    
                                     double lng2) {    
        double radLat1 = rad(lat1);    
        double radLat2 = rad(lat2);    
        double a = radLat1 - radLat2;    
        double b = rad(lng1) - rad(lng2);    
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)    
                + Math.cos(radLat1) * Math.cos(radLat2)    
                * Math.pow(Math.sin(b / 2), 2)));    
        s = s * EARTH_RADIUS;    
        s = Math.round(s * 10000d) / 10000d;    
        DecimalFormat df = new DecimalFormat("######0"); 
        return df.format(s);    
    }    
    
    public static void main(String[] args) {
    	double lati1 = 23.5;
    	double lont1 = 11.456;
    	double lati2 = 28.3334;
    	double lont2 = 45.2343;
    	System.out.println("========" + getDistance(lati1,lont1,lati2,lont2));
    }
}
